1 // P1064R0
2 // { dg-do compile }
3 // { dg-options "-std=c++2a" }
4 
5 struct X1
6 {
7   virtual int f1() const = 0;
8   virtual int f2() const = 0;
9   virtual int f3() const = 0;
10 };
11 
12 struct X2: public X1
13 {
f1X214   constexpr virtual int f1() const { return 21; }
f2X215   constexpr virtual int f2() const { return 22; }
f3X216   constexpr virtual int f3() const { return 23; }
17 };
18 
19 struct X3: public X2
20 {
f1X321   virtual int f1() const { return 31; }
f2X322   virtual int f2() const { return 32; }
f3X323   virtual int f3() const { return 33; }
24 };
25 
26 struct X4: public X3
27 {
f1X428   constexpr virtual int f1() const { return 41; }
f2X429   constexpr virtual int f2() const { return 42; }
f3X430   constexpr virtual int f3() const { return 43; }
31 };
32 
33 constexpr int (X1::*pf)() const = &X1::f2;
34 
35 constexpr X2 x2;
36 static_assert(x2.f2() == 22);
37 static_assert((x2.*pf)() == 22);
38 
39 constexpr X1 const& r2 = x2;
40 static_assert(r2.f2() == 22);
41 static_assert((r2.*pf)() == 22);
42 
43 constexpr X1 const* p2 = &x2;
44 static_assert(p2->f2() == 22);
45 static_assert((p2->*pf)() == 22);
46 
47 constexpr X4 x4;
48 static_assert(x4.f2() == 42);
49 static_assert((x4.*pf)() == 42);
50 
51 constexpr X1 const& r4 = x4;
52 static_assert(r4.f2() == 42);
53 static_assert((r4.*pf)() == 42);
54 
55 constexpr X1 const* p4 = &x4;
56 static_assert(p4->f2() == 42);
57 static_assert((p4->*pf)() == 42);
58